getrpcent.3n

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3N 代码 · 共 150 行

.\" SCCSID: @(#)getrpcent.3n	8.1	9/11/90
.\"
.TH getrpcent 3n
.SH Name
getrpcent, getrpcbynumber, getrpcbyname, setrpcent, endrpcent \- get rpc entry
.SH Syntax
.nf
.B #include <netdb.h>
.PP
.B struct rpcent *getrpcent()
.PP
.B struct rpcent *getrpcbynumber(\fInumber\fP)
.B int \fInumber\fP;
.PP
.B struct rpcent *getrpcbyname(\fIname\fP)
.B char *\fIname\fP;
.PP
.B setrpcent(\fIstayopen\fP)
.br
.B int \fIstayopen\fP;
.PP
.B endrpcent( )
.fi
.SH Description
.NXR "getrpcent subroutine"
.NXR "getrpcbynumber subroutine"
.NXR "getrpcbyname subroutine"
.NXR "setrpcent subroutine"
.NXR "endrpcent subroutine"
.NXR "group file (general)" "getting entry"
The
.PN getrpcent ,
.PN getrpcbynumber
and
.PN getrpcbyname
subroutines each return pointers
to an object
with the following structure
containing the broken-out
fields of a line in the rpc database:
.EX
.nf
struct  rpcent {               /* see getrpcent(3) */
        char    *r_name;
        char    **r_aliases;   /* alias list */
        char    r_number;      /* rpc program number */
};
struct group *getrpcent(), *getrpcbynumber(), *getrpcbyname();
.fi
.EE
.PP
The members of this structure are:
.TP \w'r_aliases'u+2n
r_name
The name of the rpc.
.br
.ns
.TP \w'_aliases'u+2n
r_aliases
A zero-terminated list of alternate names for the rpc.
.br
.ns
.TP \w'r_aliases'u+2n
r_number
The rpc program number for the rpc.
.PP
If the \fIstayopen\fP flag on the
.PN setrpcent
subroutine is NULL, the 
.PN rpc
database is opened.  Otherwise the 
.PN setrpcent
has the effect of rewinding the 
.PN rpc
database.
The
.PN endrpcent
may be called to
close the 
.PN rpc 
file when processing is complete.
.PP
The
.PN getrpcent
subroutine simply reads the next
line while
.PN getrpcbynumber
and
.PN getrpcbyname
search until a matching
.I gid
or
.I name
is found
(or until EOF is encountered).
The
.PN getrpcent
subroutine keeps a pointer in the database, allowing
successive calls to be used 
to search the entire file.
.PP
A call to 
.PN setrpcent
must be made before a 
.PN while
loop using 
.PN getrpcent
in order to perform initialization and an
.PN endrpcent
must be used after the loop.  Both
.PN getrpcbynumber
and 
.PN getrpcbyname
make calls to 
.PN setrpcent 
and 
.PN endrpcent .
.SH Restrictions
.NXR "getrpcent subroutine" "restrictions"
All information
is contained in a static area
so it must be copied if it is
to be saved.
.PP
If YP is running, 
.PN getrpcent
does not return the entries in any particular order.
See the 
.I Guide to the Yellow Pages Service
for setup information.
.PP
The 
.PN rpc
database may also be distributed by the BIND/Hesiod
naming service.  See the
.I Guide to the BIND/Hesiod Service
for more information.
.SH Return Values
A null pointer
(0) is returned on EOF or error.
.SH Files
.PN /etc/rpc
.SH See Also
rpc(5), svc.conf(5)
.br
.I Guide to the BIND/Hesiod Service
.br
.I Guide to the Yellow Pages Service